1. Field of the Invention
The present invention relates to an optical disc drive, and data recording/reproducing method, which writes and/or reads data to and/or from an optical disc, and more particularly, to an optical disc drive, and data recording and/or reproducing method, which enable a plurality of types of optical discs different in recording density from each other.
2. Description of the Related Art
There have become popular the CD (compact disc) systems in which an optical disc having an outside diameter of about 120 mm and a thickness of about 1.2 mm is used as a recording medium and a signal is read from, or written to, the optical disc by illuminating a signal recording surface of the optical disc with a light converged by an objective lens.
The CD system has initially been developed as a recording/playback system for digital audio data. As this technology has been accepted very widely, a wide variety of CD systems have so far been proposed for various applications.
Recently, the personal computers have been used as an information processing means in more and more ordinary households. Along with this tendency, a read-only optical disc called xe2x80x9cCD-ROM (read-only memory)xe2x80x9d has become popular for use to record data handled in the personal computer.
Also, a recordable optical disc such as CD-R (recordable) and rewritable optical disc such as CD-RW (rewritable) have been developed and used as optical discs interchangeable with the CD-ROM in practice.
The amount of data handled in the personal computer has become larger and larger, and thus the CD-ROM, CD-R and CD-RW as recording media for recording data have strongly been required to have an increased storage capacity.
To meet such a requirement, the so-called double-density CD-R and CD-RW maintaining the CD format and having a recording density about 2 times higher than in the current CD format are under development.
In the double-density CD-R and CD-RW, the EFM (eight-to-fourteen modulation) modulation and demodulation methods and error correction method applied to the CD-R and CD-RW having the current format (will be referred to as xe2x80x9cnormal-density CD-Rxe2x80x9d and xe2x80x9cnormal-density CD-RWxe2x80x9d, respectively, hereunder) are not changed but the track pitch is reduced while the linear density is increased, to thereby elevate the recording density up to about double that of the currently available normal-density CD-R and CD-RW. Thus, it has been tried to attain a higher recording density without having to considerably modify the circuit design while maintaining the compatibility with the normal-density CD-R and CD-RW.
Along with the development of such double-density CD-R and CD-RW, there has been developed an optical disc drive which is compatible with the double-density CD-R and CD-RW. It should be reminded that the present invention will be described hereunder taking the CD-R and CD-RW as recording media and an apparatus supporting these CD-R and CD-RW as an optical disc drive.
For an optical disc drive capable of a double-density CD-R or CD-RW, it is desired that data can properly be written to, and/or read from, the normal-density CD-R or CD-RW, an instant discrimination of an optical disc to or from which data is going to be written or read can be made among a double-density CD-R, double-density CD-RW, normal-density CD-R and a normal-density CD-RW, and various parameters necessary for data writing and reading operations can instantly be selected and the time taken for the optical disc drive to get xe2x80x9creadyxe2x80x9d for data write or read is as short as possible.
It is therefore an object of the present invention to overcome the above-mentioned drawbacks of the prior art by providing an optical disc drive, and a data recording/reproducing method, which enable a plurality of types of optical discs different in recording density from each other and also can start data write and/or read to and/or from each of the optical discs in a short time.
The above object can be attained by providing an optical disc drive capable of a plurality of types of optical discs different in recording density from each other, the apparatus including according to the present invention:
means for writing and/or reading data to and/or from each of the plurality of types of optical discs;
means for having stored therein, for each of the plurality of types of optical discs, controlling conditions under which the data writing/reading means writes and/or reads data to and/or from each of the plurality of types of optical discs; and
a disc discriminating means for determining the recording density of an optical disc to and/or from which the data writing/reading means is going to write and/or read data.
In the above optical disc, the data writing/reading means acquires, from the storing means, controlling conditions corresponding to the recording density of the optical disc, determined by the disc discriminating means, and writes and/or reads data to and/or from the optical disc under the acquired controlling conditions.
Also the above object can be attained by providing a data recording/reproducing method for writing and/or reading data to and/or from a plurality of types of optical discs different in recording density from each other, the method including according to the present invention, steps of:
emitting a light beam to the optical disc and detecting a reflected light from the optical disc;
determining the type of the optical disc based on the result of the above reflected light detection; and
selecting data write and/or read controlling conditions, stored for each of the plurality of types of optical discs in a memory, based on the result of the disc type discrimination; and
writing and/or reading data to and/or from the optical disc under the selected controlling conditions.
In the above data recording/reproducing method, controlling conditions corresponding to the type (recording density) of the optical disc, determined at the disc type discriminating step, are acquired from the memory, and data is written and/or read to and/or from the optical disc under the acquired controlling conditions.
These objects and other objects, features and advantages of the present intention will become more apparent from the following detailed description of the preferred embodiments of the present invention when taken in conjunction with the accompanying drawings.